DETROIT — Habitat loss and an especially harsh winter are proving to be a destructive combination for Michigan’s monarch butterflies.
The cold weather affected the monarchs’ migration north, causing them to arrive in Michigan later than usual, said Diane Pruden of Milford Township, a citizen researcher for Monarch Watch, a nonprofit education, conservation and research program based at the University of Kansas.
Because of their late arrival, butterflies are laying eggs later and in lower numbers this year than Michigan has seen in the past, the Detroit Free Press reported. Monarchs are usually spotted around the state in May and June, but Pruden said she only recently saw eggs for the first time this season.
Orley Taylor, the founder and director of Monarch Watch, said the monarch population has been on the decline for about 10 years. But he said it reached an all-time low this past winter.
“There’s a great deal of concern that the monarch migration is on the verge of collapse,” he said.
Monarchs only lay eggs on the wild milkweed plant. Michigan’s expansion of corn farming has reduced milkweed growth in recent years.
Taylor said much of the land in the central plains states where milkweed once prospered has been repurposed for corn crops. According to U.S. Department of Agriculture statistics, nearly 23.7 million acres of grassland, wetlands and shrub lands were converted to agriculture in this area between 2008 and 2011.
Steve Mueller, president of the West Michigan Butterfly Association, said people who want to help should plant milkweed at home to compensate for plants lost to agriculture and development.
The monarch is one of a few migratory butterflies. It travels up to 4,000 miles to Mexico every fall. The butterflies that return to Michigan are the offspring of monarchs that lay eggs in Texas and Oklahoma before dying off.